Electronic devices are commonplace throughout most of the world today. Advancements in integrated circuit technology have enabled the development of electronic devices that are sufficiently small and lightweight. Wearable electronic devices such as smart watches, smart eyeglasses, electronic rings, etc. appear and become popular because of the convenience of carrying and using. The wearable electronic devices are mostly attached or coupled to the wrist, neck and face of users. Except for pursuing of multifunction of the wearable electronic devices, the users also pay more attention to their appearance. However, a housing of the wearable electronic devices are commonly undetectable. Thus, it is difficult for the users to obtain a new appearance by changing the housing.